Maybe I am missing something here... Don't people want to know these details coming from the perspective of a specific prototype? Hence, you know what you want to figure out because you are modelling car model XXX from railroad YYY in the period ZZZ.
In a sense, don't these exist with the excellent freight car rosters that have been built up? I suppose they may not always have shots of the ends, gear, etc., but judging from the knowledge I see posted here, it would not be difficult to come up with a series of "type" images with these details, specific to railroad or model.
